package org.jeecg.modules.system.util;

import org.apache.commons.codec.binary.Base64;

import javax.crypto.Cipher;
import java.nio.charset.StandardCharsets;
import java.security.*;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;

/**
 * @ProjectName: ideaWork
 * @Package: org.jeecg.modules.system.util
 * @ClassName: RASUtil
 * @Author: 朱修轩
 * @Description:
 * @Date: 2020/9/29 19:13
 * @Version: 1.0
 */
public class AesEncryptUtil {
    private static final Map<Integer, String> KEY_MAP = new HashMap<>(16);
    /**
     * 公钥
     * MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDRYwEHVtYKjqQ5VZEzVkPJqSWwokUy7GYZdjB+aUZDNioAWPXZ3A9HlOjp5FLbHEmLtIVt7qFX0U/E8xl9Ar1rePRUOijtxRBjpWTdW9f9DCw6CY7dPcXvxCKbshf1lSYEysu3Kphb+44/meqrGKuYnqJTYQVcjNXSmtMXFto08QIDAQAB
     */
    /**
     * 私钥
     */
    public static String PRIVATE_KEY = "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";
    public static void main(String[] args) throws Exception {
        //生成公钥和私钥
        genKeyPair();
        //加密字符串
        String message = "df723820";
        System.out.println("随机生成的公钥为:" + KEY_MAP.get(0));
        System.out.println("随机生成的私钥为:" + KEY_MAP.get(1));

    }

    /**
     * 随机生成密钥对
     *
     * @throws NoSuchAlgorithmException
     */
    public static void genKeyPair() throws NoSuchAlgorithmException {
        // KeyPairGenerator类用于生成公钥和私钥对，基于RSA算法生成对象
        KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
        // 初始化密钥对生成器，密钥大小为96-1024位
        keyPairGen.initialize(1024, new SecureRandom());
        // 生成一个密钥对，保存在keyPair中
        KeyPair keyPair = keyPairGen.generateKeyPair();
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
        String publicKeyString = new String(Base64.encodeBase64(publicKey.getEncoded()));
        // 得到私钥字符串
        String privateKeyString = new String(Base64.encodeBase64((privateKey.getEncoded())));
        // 将公钥和私钥保存到Map
        KEY_MAP.put(0, publicKeyString);
        KEY_MAP.put(1, privateKeyString);
    }

    /**
     * RSA公钥加密
     *
     * @param str       加密字符串
     * @param publicKey 公钥
     * @return 密文
     * @throws Exception 加密过程中的异常信息
     */
    public static String encrypt(String str, String publicKey) throws Exception {
        //base64编码的公钥
        byte[] decoded = Base64.decodeBase64(publicKey);
        RSAPublicKey pubKey = (RSAPublicKey) KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(decoded));
        //RSA加密
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE, pubKey);
        String outStr = Base64.encodeBase64String(cipher.doFinal(str.getBytes(StandardCharsets.UTF_8)));
        return outStr;
    }

    /**
     * RSA私钥解密
     *
     * @param str 加密字符串
     * @return 铭文
     * @throws Exception 解密过程中的异常信息
     */
    public static String decrypt(String str) throws Exception {
        //64位解码加密后的字符串
        byte[] inputByte = Base64.decodeBase64(str.getBytes(StandardCharsets.UTF_8));
        //base64编码的私钥
        byte[] decoded = Base64.decodeBase64(PRIVATE_KEY);
        RSAPrivateKey priKey = (RSAPrivateKey) KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(decoded));
        //RSA解密
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.DECRYPT_MODE, priKey);
        String outStr = new String(cipher.doFinal(inputByte));
        return outStr;
    }
}
